Aiming at the problem that the key parameters of rotor modal dynamic balance

which are rotor imbalance and bearing characteristic parameters

are difficult to determine

a method for simultaneous identification of bearing characteristic parameters and rotor distribution unbalance parameters based on the vibration response at the bearing was proposed. This method used a polynomial function to describe the eccentricity curve of the rotor mass for characterizing the continuously distributed unbalanced mass of the rotor; established the motion differential equations of substructures in the system with the finite element method; converted the continuously distributed generalized unbalanced force into the concentrated generalized unbalanced force of nodes through the principle of virtual work and established the relationship between concentrated unbalanced force and eccentric curve coefficients

thereby deduced the simultaneous identifying equation of bearing characteristic parameters and mass eccentricity curve coefficients

and then realized the identification of bearing characteristic parameters and distribution unbalance parameters based on the vibration response of the bearings at different speeds. Taking a rotor-bearing system as an example

the sensitivity of the eccentric curve order to parameter identification was simulated

the results show that the order of the eccentric curve has little effect on the parameter identification results. The first-order modal dynamic balance experiment was carried out with the parameters identified from the response of the measured bearings and vibration at the bearings significantly reduced after balancing

which verifies the proposed identification method and its effectiveness in model dynamic balance.